Computer display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a computer display screen or portion thereofwith transitional graphical user interface, showing a first image in asequence according to the claimed design;

FIG. 2 is a front view showing a second image in the sequence; and,

FIG. 3 is a front view showing a third image in the sequence.

The process or period in which an image transitions to another imageforms no part of the claimed design.

The longer-incremented broken-line showing of a computer and theshorter-incremented broken line showing of a display screen of thecomputer, as well as the features within the interface (including humanfigures), are included for the purpose of illustrating environmentalstructure and form no part of the claimed design.

CLAIM The ornamental design for a computer display screen or portionthereof with transitional graphical user interface, as shown anddescribed.